Mosiah 3: 10

The angel's message in Mosiah 3: 10 is the same as Zenos' message. Zenos prophesied more than a century before Lehi left Jerusalem. His record was on the brass plates obtained from Laban. During the three days in the tomb, Zenos added the detail that the isles of the sea (which included the Americas/2 Ne. 10: 20) would be given the sign of three days of darkness. (1 Ne. 19: 10.) King Benjamin knew this information from existing scripture. Once the angel declared it, however, rather than having belief in the account based on study, he would have faith of the event because the angel told it from heaven. The Book of Mormon regularly moves one from belief, to faith, to knowledge. This is an example of moving from belief based on study of scripture, to faith based on the testimony of an angel.

Not only would the Lord rise from the dead, but He would also "stand to judge the world." That is an important reference. It identifies the Lord's status as judge, and it clarifies He would "stand" to judge the world. The word "stand" is symbolic. It implies, among many other things:
-He will endure.
-He will be in control.
-He will triumph.
-He will rise up.
-He will command respect and obedience.

However, the strongest implication is that after death He will return to life to "stand" to judge the world. He who passed through the grave, and triumphed over it, will live again as the triumphant judge of the living and dead -  for He has been both.

He gains capacity as He passes through these states. He does all these things "that a righteous judgment might come upon the children of men." Or, the judge will necessarily experience all He will go through so He can understand all things required for a proper judgment. (See D&C 88: 41.)

God's mercy is extended to all who have "fallen by the transgression of Adam" or, the death that comes upon mankind will be defeated. (D&C 88: 14-17.) Christ's death, or His "blood atoneth" for mankind's death. Through the infinite sacrifice of an innocent life, death is satisfied. It would be unjust to ask for more than an everlasting life, for by definition that life is infinite. Christ deserved everlasting life. Instead He submitted to death.

"The sins" of Adam's descendants are paid, also. He will blot them out. However, those who refuse to repent, or turn away from their sins will remain "filthy still." (D&C 88: 35.) They may have the power to return from the grave through Christ's grace. However, if they refuse to abandon their sins, forgiving them will accomplish nothing. Because they love their sins, they remain as if there were no redemption made.

All those who died without knowing the will of God are also benefited by His atonement. For them it will be "tolerable" in the day of resurrection. (D&C 45: 54.) Though they may not have received a fullness because they failed to qualify (D&C 130: 20-21), they may still be "added upon." (Abr. 3: 26.) Joseph explained it this way: "When you climb up a ladder, you must begin at the bottom, and ascend step by step, until you arrive at the top; and so it is with the principles of the gospel—you must begin with the first, and go on until you learn all the principles of exaltation. But it will be a great while after you have passed through the veil before you will have learned them. It is not all to be comprehended in this world; it will be a great work to learn our salvation and exaltation even beyond the grave." (King Follett Discourse, TPJS, p.348.)

No one can arrive at the throne of God in any other way than all have taken to arrive there. Everyone develops the same way, through the successive stages of Jacob's Ladder.

Christ's atonement makes it possible for all of us to attempt that trek.